1. Field of the Invention
This invention relates to a method of preparing liquid compositions for delivery of N-[N-(3,3-dimethylbutyl)-L-α-aspartyl]-L-phenylalanine 1-methyl ester in food and beverage systems.
2. Related Background Art
N-[N-(3,3-dimethylbutyl)-L-α-aspartyl]-L-phenylalanine 1-methyl ester (hereinafter “neotame”) is an extremely potent sweetening agent, as disclosed in U.S. Pat. No. 5,480,668, the complete disclosure of which is incorporated by reference herein. Its sweetening potency, on a weight basis, is reported to be about 6,000 to about 8,000 times that of sucrose and about forty to fifty times that of aspartame.
As with aspartame, a major application for neotame is as a low calorie sweetener in the food and beverage industries. Neotame is sold in bulk to the various food and beverage manufacturers who must then repackage the sweetener and distribute it to their various bottlers and distributors.
Neotame in bulk is commercially available in various forms: powder, granulated and agglomerated. The granular form of neotame has high bulk density and possesses good flow properties but does not always instantaneously dissolve. In contrast, neotame powder has low bulk density and good dissolution properties, yet, due to its lower bulk density and small particle size, is readily air-borne and can present dusting and flow problems. In particular, the extremely high potency of undiluted neotame renders its powder dust potentially irritating during handling and transport. These properties can result in product losses and metering problems, and create a need for expensive packaging and shipping containers as well as protective gear. The equipment expenditures used to offset these problems can substantially increase production costs of the food or beverage product sweetened with neotame.
The use of a liquid delivery system, whereby neotame is delivered via a stable liquid composition to the food or beverage system, would bring about a number of key advantages. Carbonated soft drink manufacturers would be spared inconvenience and cost by having an all liquid production system that avoids handling of solid neotame, particularly in its powder form. In addition, adjustment of the food or beverage formulation would be minimized because neotame's high potency requires less neotame to sweeten the product. A further advantage would be the relative ease of metering a liquid neotame composition as compared to a solid form. Due to neotame's extremely high potency, food and beverage manufacturers must be able to precisely meter the addition of neotame to their products.
While use of a liquid delivery system would theoretically minimize handling and metering problems as compared to a solid form, experience with other high intensity sweeteners such as aspartame, acesulfame-K, sucralose and saccharin, would suggest that the means for producing liquid compositions to deliver high intensity sweeteners is limited. Many high intensity sweeteners lack sufficient solubility in water (about 1%) and alcohols (less than 0.1% for aspartame in ethanol) and thus must be viscosified by thickening stabilizing agents such as gums or other polymers. For example, U.S. Pat. No. 4,722,844 to T. Ozawa et. al. teaches the preparation of aqueous aspartame dispersions by addition of a viscosity or specific gravity increasing component, such as food gums and polysaccharides. This reference however, discloses aqueous suspensions that must be either shaken before use, or alternatively viscosified by the addition of stabilizing agents. Moreover, this reference requires the presence of water, and further indicates that an amount of aspartame in the dispersion must be maintained in an undissolved state.
The limited solubility of aspartame and other high intensity sweeteners therefore presents the need for either a higher volume of liquid carrier or alternatively, a thickening stabilizing agent. The addition of more liquid carrier or a thickening stabilizing agent may however, adversely affect the viscosity, appearance, taste, texture or mouthfeel of the food or beverage product. Moreover, the limited solubility of high intensity sweeteners such as aspartame, sucralose, saccharin or acesulfame-K may require additional expense and labor for agitating or stirring the powder into the liquid.
It would thus be desirable to prepare a liquid composition of neotame for delivery in food and beverage systems that avoids the above problems encountered with other liquid formulations of high intensity sweeteners: the resulting liquid neotame composition would have minimal effect on the final formulation of the food or beverage product; would provide improved handling for shipping and transportation; and most significantly, would not result in any noticeable change in sweetness, appearance, taste, texture or mouthfeel to the final food product. It would be further desirable if neotame may be fully dissolved or suspended in the liquid composition to preclude the need for shaking the composition prior to delivery, or for viscosifying the liquid composition with stabilizing agents. It would also be advantageous if the liquid composition could deliver the desired amount of neotame without adding significant calories.